How To Set Up An Indoor Grow Room For Cannabis

Whether starting with a single grow tent, a stealth grow box, or a full scale commercial marijuana grow room, how you set up your growing space goes a long way in determining your final yields. In this chapter we'll cover the 6 most important factors for setting up a successful grow room for your cannabis plants. 

Growing indoors will provide you the power to influence all necessary inputs for growing big, healthy, cannabis plants with those big, sticky buds you dream of. This includes lights, nutrients, water and humidity, ventilation as well as temperature. Instead of being dependent on weather and soil you can optimize your production for maximum yield.

A Grow Room That Your Plants Will Love

Setting up a growing facility isn't cheap. Even the basics requirements needed can add up cost-wise. The main advantage is that indoors you are protected from natural challenges and road blocks. So setting up might be more complicated than outdoors but the results and your margins will be a lot greater. Testing things out with a single grow box might be a good solution to get started because they provide many factors needed for growing growing cannabis on a small scale.

You are probably looking for a strain that grows quickly, is easy to grow, produces much bud and has high potency. But wait… there is more to it!

Always keep in mind that the general idea is to create an environment where your plants will prosper. The better they carry out their photosynthesis, the better your output in regards of quantity and quality, what growers refer to as "yield". We will now study in great detail what your plants need:

1. Light: Lamps, Reflector and Wall Color

Your plants need light to carry out photosynthesis. However: Find a room that is completely lightproof. This will allow you to carefully choose the hours of light and darkness. In the vegetative phase your plants will need 18 hours of light, 6 hours of darkness. In the flowering phase 12 hours of light and 12 hours of darkness.

You can choose LED or HPS/MH lighting for your indoor production. A 400-Watt for vegetative phase and a 600-Watt HPS lamp for flowering phase for every square meter will be a great start. If you can make the investment use LED lamps because they will last forever, and the technology is finally catching up to the HID (HPS and MH) lamps most professional growers have used for years. See our full info on lights here.

To make the best out of your lighting use reflective walls. White walls work best for reflecting light, whilst dark or black walls will absorb the light.

Use a time switch to make things easy for you and create the best lighting experience for your plants.

2. Ventilation and Air Circulation

Make sure to find a room or grow tent that is airtight. The stench of marijuana could easily reach and bother your surroundings. Whilst air circulation and fresh air is very important, make sure that all your out-going air will pass through a carbon filter. An air extractor will remove the heat for the lamps to keep the temperature stable as well as remove the odour of the plants.

Your plants will need fresh air as well. During photosynthesis the plants take CO2 (carbon dioxide) and transform it into oxygen and sugars. The closed environment of a grow box will need a hole or entry point to supply fresh air and CO2 for your plants.

Use a fan for consistent air circulation. This way temperature and CO2 will spread evenly throughout the room.

3. Watering System and Humidity in a Grow Tent

Water running from your pots to the floor is inevitable. So best to keep your house and production safe with a waterproof floor.

Find our article on the perfect amount of water for your plants.

Humidity describes the amount of water in the air. You will need just the right amount of moisture in the air that will push the growth of your plants will at the same time not too much humidity because it will cause fungus and mold.

4. Temperature

As said in the part about air circulation, an airflow system and a fan will help you to prevent overheating of your plants.

Temperature is crucial for the photosynthesis of your plants and more over for the tasting for your results. Make sure to align the temperature to the hours of light and darkness. You gonna want a higher temperature throughout lighting time than during darkness.

Best temperature will be 77. Don’t go below 64 and don’t go higher than 86. The lamps should provide enough heat during the day. However consider that you might need extra heating during the night.

5. Nutrient Delivery

Nutrients are vital for the health of your plants. Make sure to measure them on a regular basis and change your actions accordingly. It will be important to provide nitrogen, potassium, and phosphorus for your plants.

There are different nutrients blends that you can use. It will also depend on the growing cycle of your plants, and you'll need to be careful not to go overboard and burn your plants with too much. Nitrogen toxicity is a common downfall of too many grows.

6. Security

Make sure to seal your windows and use a carbon filter against the marijuana scent. Think about using extra locks or even cameras especially when growing in a warehouse. Don’t put your crop at risk.

Think about different scenarios and how you could prevent them. Better act now than in crises.

Creating the right lighting, air flow, humidity and temperature will change your production output massively. A grow room will provide a unique learning and business experience for you.

The Cannabis Grow Room Setup Checklist

Below is a quick checklist for setting up your grow room. Each of these steps has more to them than what we can include here, but not to worry, we'll go into each in detail in the coming chapters. But for now, this is a good general checklist to follow:

  • 1. Create a blueprint. Whether you choose a basement in a residential area or a warehouse it is best to start with creating a blueprint for growing indoors. How many square meters you have will largely determine how many plants you can put.
  • 2.Prep the space. Make sure to remove all things not needed like carpets, decoration and furniture, and that you have electricity and plumbing accessible in the right proximity to where you plan to place your pots and lights.
  • 3.Set up the light and water systems. Hang your light fixtures, run the necessary wiring, plug them in and test each one. Connect and test the water system. 
  • 4.Prep the pots. Lay out your pots, soil/growing medium and seeds/clones in the appropriate quantity and arrangement according to your blueprint. Make sure everything is going to line up as expected and you have the right quantities of everything you need.
  • 5.Start planting. More on this to come in Chapter 3!

As we shared before, a grow tent can be a quick and easy introduction to growing hydroponics. These steps can be scaled up or down to any size, so often it's best to work through the kinks and see the process through with a single plant or handful of plants before scaling up.



  • Hello,

    Firstly i would like to congratulate you for the great quality work you produce.

    I am long time cannabis user, however i have now decided to start my own small growing tent. Since I live in a country that canabis is illegal, i want an equipment that will not raise any suspicions from the electricity bill or from the noice. I will growing autoflowers that don’t take too long to grow and i prefer a tent that is not bigger than 70cm×70cm×160cm and combine it with a led light and a efficient carbon filter.

    Now, when it comes to lighting and cabron filter it is not clear what equipment to take that can match with the low profile i want to keep and also be good quality at the same time.

    Could you possibly please give me some recommendations on what equipment i should purchase based on the above mentioned details.

    For any additional information you might need, I remain at your disposal.

    Kind regards,

  • Great information throughout this site! Greenlight Distribution offers a one-stop shop for grower supplies. Visit our site for more information and free quotes on cannabis grower products. www.growwithgreenlight.com

    Greenlight Distribution
  • Went organic for my cannabis nutrients. Product called BigBudJuice.ca

  • You can transform the walls of your grow room into a permanent air ionization system. Eliminating any potential contamination from Powdery Mildew-Botrytis-Gray Mold-Bacteria-Viruses-Mold Spores. Simply mix the ionic paint additive with interior house paint and apply the blended mixture to the walls of your grow room. One application produces 139.600 Anion Output Per Cubic Centimeter, your plants will produce greater yields and your employees will have a healthy environment to work in.

    Vincent Valle
  • Hello, we offer back up off-grid solar kits for grow rooms and hydroponics. Want to set up a link? Here is it if you are interested. https://theinverterstore.com/product-category/grow/

    Laura deJong
  • I don’t know if I am in the right section but anyways Is anyone here has a piece of knowledge or experience about Germinating marijuana seeds? A new way of germination and growing cannabis vines move seeds in the air and space to grow it and in a vented container swing the container in a different direction. I also grow faster and produce more (OVERNIGHT GROWTH). Will work for other products spray the air with the moisture ingredients (water flavored sugar) and aerated container in moist ingredients environment. Counterclockwise and clockwise thermodynamics wishy-washy field motion is what a sphere with a cylinder in the middle to hold the seed it does hold in all ways. Like a ceiling fan motor or plastic bag. As I do some research, I have read an article about germinating kylekushman.com/prometheus-pipe-titan-with-oil-kit/

    Margie Ridgen
  • Researchers found the helpful side of Cannabis. Cannabis is known as for addiction only but now it can be our Alternative Medicine. Cannabis now has many benefits that will be good for your health. Cannabis oil is produced by extracting the resin of the female cannabis plant using a solvent. After the resin is dissolved in the solvent, It is evaporated leaving a concentrated extract behind. CBD Oil is a type of oil that contains CBD but does not contain THC which can give you a high efficiency. CBD Oil is from that cannabis flower, However, Cannabis now is proven that can help people to relieve pains or lessen seizure attacks. I have read many articles suggesting that cannabis has a very potent effect when it comes with pain and inflammation like this strain on blimburnseeds.com/news/marijuana/medical/effects/what-is-and-how-to-fight-palida/

    isabelle butler
  • Would like to know how tall I need my ceiling. And which is the better space to set up my grow . 1st room is 12′ × 48′ -second room is 24′×24′ ceiling are not built yet.

    Tommy Sabala
  • There are more lighting technologies suitable to cannabis than LED, HPS and MH. Theres also CMH and Plasma. Plasma is expensice watt/watt but CMH is a great option. They come in 315 and 630 watt fixtures. Curious why for a great start someone would buy 2 lamps a 400 and a 600 for flowering? If you were to expand even a little that wouldn’t be the best choice anyways since the 600 is most efficient. Also LED may last longer but that doesn’t make their spectrum as good as recent advances in HID technology meaning it would all depend on certain price points.

  • Hello. My name is Jed, and I’m working on a new ITV drama in the UK, called ‘Wild Bill’.
    For one of our scenes, we find an abandoned cannabis production in an old war bunker.
    We need to try and re-imagine this scene with props etc…
    The room is about 30ft long and 16 ft wide. We were going to re-create a square section in the middle where the cannabis was grown.

    I was wondering if you could help with how many lights and what type we would need, what type of pots, generally what type of stuff we could buy to make it look like an abandoned cannabis production. Also what would weed look like after 5-10 years, would it be completely decomposed or look like withered leaves. Any help would be much appreciated. Thank you!

    Jed Bessell

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